Change uses of base::JoinString to pass StringPieces where possible.

components/autofill/content/renderer/autofill_agent.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/autofill/content/renderer/autofill_agent.h"
 
 #include <stddef.h>
 
 #include <tuple>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/i18n/case_conversion.h"
 #include "base/location.h"
 #include "base/metrics/field_trial.h"
 #include "base/single_thread_task_runner.h"
+#include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "components/autofill/content/renderer/form_autofill_util.h"
 #include "components/autofill/content/renderer/page_click_tracker.h"
 #include "components/autofill/content/renderer/password_autofill_agent.h"
 #include "components/autofill/content/renderer/password_generation_agent.h"
@@ skipping 399 matching lines @@
 }
 
 void AutofillAgent::DoAcceptDataListSuggestion(
     const base::string16& suggested_value) {
   WebInputElement* input_element = toWebInputElement(&element_);
   DCHECK(input_element);
   base::string16 new_value = suggested_value;
   // If this element takes multiple values then replace the last part with
   // the suggestion.
   if (input_element->isMultiple() && input_element->isEmailField()) {
-    std::vector<base::string16> parts = base::SplitString(
+    std::vector<base::StringPiece16> parts = base::SplitStringPiece(
         input_element->editingValue().utf16(), base::ASCIIToUTF16(","),
         base::KEEP_WHITESPACE, base::SPLIT_WANT_ALL);
     if (parts.size() == 0)
-      parts.push_back(base::string16());
+      parts.push_back(base::StringPiece16());
 
-    base::string16 last_part = parts.back();
+    base::string16 last_part = parts.back().as_string();
     // We want to keep just the leading whitespace.
     for (size_t i = 0; i < last_part.size(); ++i) {
       if (!base::IsUnicodeWhitespace(last_part[i])) {
         last_part = last_part.substr(0, i);
         break;
       }
     }
     last_part.append(suggested_value);
     parts.back() = last_part;
 
@@ skipping 363 matching lines @@
 void AutofillAgent::LegacyAutofillAgent::OnDestruct() {
   // No-op. Don't delete |this|.
 }
 
 void AutofillAgent::LegacyAutofillAgent::FocusChangeComplete() {
   if (agent_)
     agent_->FocusChangeComplete();
 }
 
 }  // namespace autofill